【摘要】 采用机械搅拌与高能超声复合分散法制备了碳纳米管增强CNTs/AZ91D镁基纳米复合材料。利用金相显微镜、扫描电镜、拉伸试验等手段观察和测试了复合材料的微观组织与力学性能,并利用扫描电镜和能谱分析对复合材料断口形貌、成分进行了观察和分析。结果表明,半固态机械搅拌与高能超声处理能使碳纳米管较好地加入且均匀分散到AZ91D镁合金基体中。CNTs加入量在0~1.0%范围内,随着CNTs加入量的增加,复合材料的强度和塑性同时得到了提高。CNTs含量为1.0%的AZ91D镁基复合材料铸态的抗拉强度、屈服强度、伸长率分别达到200 MPa、114 MPa、5.4%,与基体合金相比,分别提高了51.5%、42.5%、170%,碳纳米管主要起到细化晶粒和承受变形载荷的作用。更多还原

【Abstract】 Carbon nanotubes(CNTs)reinforced AZ91Dmagnesium matrix nanocomposites were fabricated by mechanical stirring combined with ultrasonic vibration dispersion.Microstructure and mechanical properties of CNTs/AZ91Dcomposites were investigated by optical metallographic microscope(OM),scanning electronic microscope(SEM)and tensile test,and fracture morphology of the tensile samples was also observed by SEM and energy spectrum analysis(EDS).The results show that carbon nanotubes can be added smoothly and distributed dispersedly in the AZ91D magnesium matrix alloy by the semi-solid mechanical stirring and high-energy ultrasonic treatment.When CNTs addition is in range of0~1.0 %,with the increase of CNTs content,tensile strength and elongation of the composites prepared are improved obviously.Tensile strength,yield strength and elongation of 1.0% CNTs/AZ91D magnesium matrix composites reach 200MPa,114MPa and 5.4%,respectively,compared with those of matrix alloy,increased by 51.5%,42.5%and by 170%,respectively,showing excellent comprehensive mechanical properties.Carbon nanotubes mainly play the role in refining grains of the nanocomposites and bearing deformation loading.更多还原